Hydraulic brake mechanism



Oct. 14, A. L. LEE HYDRAULIC BRAKE MECHAISM Filed June 30, 1944 2Sheets-Sheet 1 ATT'Y Oct. 14, 1947. A. l.. LEE 2,429,163

HYDRAULIC BRAKE MECHANISM Filed June 50, 1944 l 2 sheets-Sheet 2 se ,Glsca G' 4g 4G 5G 60 4c 58 54 55 5*' 5o 55 7 7 l/l/ Af f S350 1 U c nF9731/ 46 5G 18,5/ E96 3| |48 6s 5G 52 4G 53 INVENTOR; ARTHUR l.. LEE,

Patented Oct. 14,' 1947 y joFElcE 2.429.163v HYDRAULIC BRAKE MECHANISMArthur L Lee, UppervArlington,

assignments,

by me'sne factoring Ohio, assignor,

to The Jem-ey Manu- Company, a corporation of Ohio Application June 3o,1944, serial No.

s claims. (o1. 18s- 151)l anism.

A further object of the invention is to provide a brake mechanismincluding a hydraulic actuator fluid motor which contracts uponactuation.

Still another lobject of the invention is to provide a brake mechanismincluding an actuator as well as an actuator per se which is ofextremely simple construction and which may be readily replaced as acomplete unit.

Other objects of the invention will appear hereinaifter the novelfeatures and combinations being set forth in the appended claims.

In the accompanying drawings,

Fig. 1 is a side elevational view of a brake mechanism includingfeatures of my invention;

Fig. 2 is an end elevational view of the apparatus of Fig. 1;

Fig. 3 is a sectional view taken on the line 3 3 of Fig. 1, looking inthe direction of the arrows;

Fig. 4 is a sectional view through the hydraulic motor or actuator whenit is in its normal or open position;

, Fig. 5 is a view similar to Fig. 4 with a motor or actuator in itsactuated, operated or contracted position;

Fig. 6 is a side elevational view of the motor oractuator per se whichcomprises as a unit and alone a feature of my invention, the motor beingillustrated in the normal, open or nonactuated position; i

Fig. 7 is a longitudinal sectional 'view taken on the line 1 1 of Fig.6, looking in the direction of the arrows;

Fig. 8 is a transverse sectional view taken on the line 8-B of Fig. 6,looking in the direction of the arrows;

Fig. 9 is a perspective view of one part ofthe hydraulic. actuator ormotor;

Fig. 10 is a perspective view of another part of the motor or actuator;and

Figs. 11 and 12 are sectional views of two modied forms of motors oractuators illustrated in their contracted, actuated or operatingpositions.

Referring first to Figs. 1, 2 and 3 of the drawings, .as illustrated,the brake mechanism conillustrated in Fig. 3 of the stitutes one aspectof my'invention. Said mechanism includes a U-shaped yoke or frame member20 which, itself, is of generally U-shaped structure as viewed incross-section, as clearly drawings. The lfree ends or bottom of the yoke20 are connected to a frame or supporting member 2| by spacedbolts 22which extend through cross webs formed adjacent said free ends of saidyoke 20.

Within the yoke 20 is a brake drum 23 upon which there floats a brakeband 24 provided with brake lining material 25. The brake band andlining 24 and 25 float freely on the drum 23 and preferably extend overthe periphery thereof through an, angle only slightly less than 360degrees and preferably in excess of 270 degrees so that it will have aself-energizing action as hereinafter pointed out more completely.

The spring of the brake band 24 is such that whenever said brake band isreleased it tends to release the drum 23 for free movement. The freeends of the brake band 24 carry abutments or shoes 26 and 21 each havingan abutting connection as hereinafter described- Cooperating with theshoe 26 is an adjustable abutment screw 28 which is threaded through ablock formed in the lower end of a pivoted arm 29, the upper end ofwhich is4 pivotally connectedto the top of the yoke 20 by aI pivot pin30 and the bottom of which is pivotally connected to a hydraulic pistonmotor or actuator 3| by a pivot pin 32. The abutting or inner end of theabutment screw 28 is preferably roundedand extends into a depression inthe shoe 26, thus providing a loose but abutting connection betweentheabutting head of said screw 28 and said shoe 26. The outer end i of thescrew 28 is provided with a screwdriver "I'he lower end of the arm Of.the yoke 20 in order to reach motor 3l.

slot 33 to provide for ready turning and consequent adjustment thereof.A cotter key is preferably provided which extends through the arm 29 andlocks the screw 28 in any adjusted position.

Having an abutting connection with shoe 21 is an abutment screw 34 whichis identical in structure with screw 28 and issupported in a blockformed in the lower end of an` arm 35 similar to arm 29, in that the topthereof is pivoted by the pin 30 and the bottom is pivoted bya pin 36 tothe opposite end of the piston motor or actuator 3l. The relationbetween the abutment screw 34 and associated shoe 21 is the same as thatdescribed for screw 28 and shoe 26. 35 extends through the bottomportion Outan opening 31 (see Fig. 2) in the device. `a mechanism andobviously there are others.

ward movement oi the lower end of the arm 35 is limited by a cross headabutment 38 which extends from opposite sides thereof and cooperateswith abutments 39 on the yoke 20. The arm 29' extends through an openingin the yoke 20 similar to opening 31 and cooperating abutment means 40and 4| are formed on the arm 29 and yoke 20 to restrict the outwardmovement of the lower end of said arm 29.

Before describing in detail the structure oi the piston motor oractuator 3| -which per se and also in combination forms an importantfeature of my invention, it may be stated that said piston motor oractuator 3| is normally in the expanded position, as illustrated in Fig.1 of the drawings. Under these conditions, the lower ends of the arms-29and 35 will be swung outwardly to their extreme positions with abutments38 and 39 in contact and abutments 40 and4| in contact. This relation ofparts is because of the structure of the piston motor or actuator 3l, ashereinafter described. With the parts in this position the brake band 24will be released since the screws 28 and 34 will be adjusted withrelation to their shoes 26 and 21 respectively, so as to effect suchreleasing, under the conditions described and illustrated in Fig. 1 ofthe drawings. The brake drum 23 will therefore be free to turn with thebrake band 24 and lining 25 floating thereon, that is, the brake band 24and 25 have no connection to any other apparatus except the abuttingconnections provided between shoes 26 and 21 and screws 28 and 34,respectively, and the floating relation of the brake lining 25 on saiddrum 23.

Adjustment of the maximum expansion of the brake band 24 is provided bythree eccentric brake adjusting devices 42 which are carried by the yoke20 and equally spaced about the periphery of the drum 23, preferablybeing located 120 degrees apart. Each of these eccentric brake adjustingdevices 42 is merely a bolt mounted for rotation on its axis in the yoke29 and provided with a pair of spaced eccentrics or cams 43 theeffective distances of which from the brake band 24 may be adjusted byrotating the bolt as provided by a screw driver slot 44. A locking nut45 is provided to lock each adjusting device 42 in any adjustedposition.

Attention is now directed particularly to Figs.

4, 5, 6, 7, 8, 9 and 10, and to the detailed construction of thehydraulic piston motor or actuator 3|. Said piston motor or actuator 3|is of the fluid actuated type and preferably is actuated by a liquidsuch as hydraulic oil. One of the outstanding characteristics of saidmotor or actuator is the fact that upon operation or actuy ation itcontracts rather than expands and consequently it may be directlyconnected to any mechanism where it is desired to shorten the distancebetween two points upon actuation of A'brake is one illustration of suchFor example, the actuator might be employed to swing the rudder of aboat or airplane or to control other parts thereof or of any other widevariety of devices. In other words, the actuator per se will have agreat many uses in addition to the specific use illustrated andconsequently in one aspect of the invention the actuator aloneconstitutes an important feature thereof.

Said motor or actuator 3| includes a body member in the form of cylinder46 which is closed at one end by a closure member 4,1, The

` slide into the cylinder 45 and have a close iit between the externalcylindrical surface of the piston 48 'and the interior cylindricalsurface of the cylinder 46. At the right hand end or, in other words,adjacent its open end, the body or cylinder 46 vis provided with aconnecting bifurcated head' 49 which is-in the form of two spaced apartmembers which head provides for pivotal connection with some member tobe actuated such as the brake arm 35, the spaced members of said head 49being provided withl aligned pivot pin receiving holes or openings 50 toreceive the pivot pin 36.' Obviously the head 49 provides a connectingmember by which one ,vend of the piston motor or actuator 3| may bepivotally connected to any device which is to be actuated or operated. v

Looped about the cylinder 46 and the piston 48 is a loop formed by aU-shaped yoke 5I, which yoke 5| is formed of a pair of parallel sidebars or straps 52 interconnected at one end by a crosspiece or cross-bar53 which forms a base of said U-shaped yoke 5|. Said base, cross-pieceor cross-bar 53 preferably has a bearing area 54 which 1s a segment of asphere though any desired shape may be employed which provides anextended bearing area of contact with the right hand, rear or bottomportion `of the piston 48 which is of complementary structure. Thus thepiston 48 and yoke 5| have only an abutting oneway connection betweenthem, that is, piston 48 can move the yoke 5| to the right relatively,as seen in Figs. l, 4, 5, 6 and 7 of the drawings, or the yoke 5| canmove the piston 48 to the left relatively, as seen in said figures ofthe drawings, but reverse relative motion cannot be positively effected.

The yoke 5| is provided with a rigidly attached head or cap 55 which ispreferably permanently attached to said yoke as a iinal act of assemblyof the parts by welding the free ends of the side bars or straps 52thereto, as illustrated by the welds 56. It is the intention of theinventor that the piston motor or actuator 3| when damaged or worn outshall be replaced as a complete unit and it is for this reason that thehead or cap 55 is welded to the yoke 5|. If it is desired to make theunit so that it can be disassembled, the yoke 5| may be attached to thehead or cap 56 by screws or the like. It will be noted, particularly byreference to Figs. 8 and l0 of the drawings, that the externalconfiguration of the cylinder 46 is such as to provide guideways 5l forthe side bars 52 of the yoke 5| which provide forward axial orlongitudinal movement between the yoke 5| and the cylinder 46. The capor head 55 is provided with a hole or opening 58 which provides for itspivotal connection to a mechanism to be operated, which in theillustration of my `invention is the arm 29, the pivotal connection theprojections 58 and the bosses 80 and abut the bases of each of them,thus urging the heads 48 and 55 apart. that is, urgingthe hydraulicpiston motor or actuator 3| `to the fully expanded position or, in otherwords', to its normal or open position, as illustrated in Figs. 1, 4, 6and 7 of the drawings.

To provide for actuation and contraction of the hydraulic piston motoror actuator 3l there is a threaded feed opening 62 (see Figs. 8 and 10)vprovided adjacent the closed end of the cylinder 46 by which thehydraulic fluid such as oil is delivered to the interior of tween theclosed end 4l and piston tc. Obviously the introduction of hydrauliciuid under pressure through the feed opening 62 will cause rela-t tivemovement between the cylinder it and piston 48 which, due to themechanical linkage above described, will cause rectilinear movement ofthe two heads dil and 55 toward each other. The limits of thisrectilinear movement are indicated by comparing Figs. 4 and 5 of thedrawings.

From the'above descriptionit is obvious that the piston motor oractuator 3| is a very compact device. The parts are simple and rugged.It is direct acting and contracts upon actuation. It may be noted thatthe pin receiving holes 50 and 58 lie in a plane or along an axispassing through the center or axis of the cylinder 48 and piston 48. Asa consequence there is no turning movement which requires compensationbut true rectilinear motion is produced along the axis of the actuatoras a unit. In view of the simple and inexpensive construction of theactuator it is contemplated, that in any case where parts becomeexcessively worn, the actuator will be replaced as a complete new unit.However, as above mentionedj/ by making the cap or head 55 removable, itmay be disassembled and repaired and I contemplate such a structurewithin the broad scope of my invention.

In Fig. 11 of the drawings I have shown a modiilcation of the actuator,the modied structure being confined to the piston |48 which isessentially a two-part device provided with well known type of packing83 to insure a iluidtight t between the piston |48 and the cylinder t6.

In Fig. 12 of the drawings I have shown another modiiied form of piston248 in which there is provided a circumferential groove which receives arubber sealing ring 64 which, as well understood in the hydraulic art,provides a fluid'- tight packing between the piston 248 and the cylinder46. Except for the 'diil'erences illustrated, the piston motors oractuators of Figs. 11 and 12 follow the structure previously described.

VTo review brieily the operation of the apparatus in its complete formas illustrated in Fig. 1 of thedrawings, the brake band 24 and lining 25oat freely on a brake drum 23. The spring action of the brake band 24 issuch that it tends to expand to a larger cylinder than the drum 23 andthus release itself. The pivotally connected .arms 29 and 35 whenactuated by the piston motor or actuator 3| swing about the pivot pin 30and through the abutting connection provided by screws 28 and 34 andabutments 26 and 21, respectively, contract the brake band 24 to applythe braking action. The brake is not only full iloating but is of theself-energizing type for each direction of rotation of the drum 23. thatis, as the brake band 24 is contracted the rotation of the drum 23 willaid in the braking action since friction betweenit and the brake lining25 will tend to increase said braking action. This is due said cylindert6 and beac aaios particularly to the fact that the brake band is i'ulliloating and iscontinuous between the point of contact of one shoe, suchas shoe 28, to the other shoe, such as shoe 21, andthe brake bandextends through a large portion of the circumference of the drum 28, andis preferably extended over 270 degrees thereof.

Referring more in detail to Fig. 1, it is to be noted that the arms orlevers 28 and 35 are pivoted to the pin which is positioned above theupper or central eccentric brake band adjusting or positioning device43. The eccentric devices 08 are adjusted so that the central axes ofthe brake drum 28 and the brake band 2d are coincident when the brake isreleased, that isl when the brake band is expanded against all of theeccentric adjusting or positioning devices d3. Because of the particularpositioning of the pivot pin 3@ upon which the arms or levers areplvoted, the levers when moved toward one another cause the abutments ofthe screws 28 and 34 to swing in long arcs which very gradually approachthe brake drum, thus when the levers 29 and 35 are moved toward oneanother the heel and toe respectively of the brake band also travel inarcuate paths which correspond to the paths of travel o1' the abutmentscrews 28 and 34. This particular construction and arrangement of thelevers 29 and 35 and the brake band 24 causes the brake band to be drawnuniformly about the brake drum and to oat thereon before any brakingpressure-is applied upon vthe brake band, that is, the toe and heelofthe band are not permitted to drag upon the brake drum while the brakeband is being contracted about the drum prior to the application ofbraking pressure thereto, but when braking pressure is applied the toeand `heel of the-band act vupon the drum. In other words, the axis ofthe brake band is at all times maintained substantially coincident withthe axis oi the brake drum. The brake band remains circular and iscontracted in such manner that substantially all of the irictional areacontacts the brake drum substantiallyl simultaneously and then brakingforce is applied to it.

With this construction and arrangement of the levers and full oatingbrake band the levers 28 and 35 form the sole anti-rotational anchoringmeans for the brake band when it is contracted upon the brake drum andthe brake is full selfenergizing for either direction of rotation of thebrake drum, that is, the brake drum tends to wind the entire brake bandabout itself which increases the braking eiect and tends to reduce thepressure required to move the levers 28 and 85 toward one anotherbecause the abutment on the toe or leading edge of the brake band ispulled against the abutment screw 28 or 34 and this force is transmittedthrough the lever 29 or 35 to the frame 20 through the pivot pin 80.

It is to be particularly noted that the actuator 8| has its heads 49 and55 directly and pivotally connected to the free ends of the brakeactuating arms 29 and 35 and that upon the application of hydrauliciluid to the piston motor or actuator 3| the overall length other wordsit contracts, in response to actuation or application of hydraulic iiuidpressure. In short, the actuator has its heads directly connected to thetwo members, namely arms 29 and 35, which are to be pulled toward eachother. This obviouslymakes for a very simple, direct acting positivetype of piston motor or actuator and eliminates the-necessity of theusual reversing thereof decreases, or, in

linkages found in expanding types of brake mechanisms or otheractuating` devices.

Obviously those skilled in the art may make various changes in thedetails and arrangement of partswithout departing from the spirit andscope of the invention as to the precise construction herein disclosed.

f Having thus described and shown an embodiment of, my invention, what Idesire to secure by Letters Patent of the United States is: 1. Aself-energizing brake mechanism including abrake drum, a one lpiecebrake band freely floating on vsaid drum and extending over theperiphery thereof in excess of 270 degrees, abutments on the free endsof said brake band, spaced eccentric means having only an abuttingcontact with Isaid band for adjusting it toward and from said drum, andoperating mechanism having abutting connection only with said abutmentsand adapted to exert pressure on them andcontract said brake band onsaid drum while maintaining the axes of ksaid brake band and drumsubstantially coincident thereby contracting said brake band uniformlywhereby all of the frictional area thereof is brought substantiallysimultaneously into contact with the brake drum and thereafter to exertpressure upon said abutments to contract said brake band to applybraking pressure.

2. `.d reversible balanced self-energizing brake 4mechanism including incombination a frame, at

least three spaced adjustable eccentric brake band positioning memberscarried by said frame, a brake drum adapted to rotate in said frame, aone piece brake band adapted to float upon said drum extending over theperiphery thereof in excess of 270 degrees, said brake band'beingnormally expanded away from said drum and against said spaced eccentricbrake band positioning members when said brake mechanism is inoperative,abutment means secured to opposite ends of said brake band, said endsand abutments beingV positioned between a pair of said adjustableeccentric brake band positioning members, a pair of levers pivoted tosaid frame opposite said abutment members, adjustable means abuttinglyconnecting the free end of each of said levers with the adjacentabutment means, stop means carried by each of said levers adapted tocooperate with said frame for limiting expansive swinging movement ofsaid levers, and a floating operating mechanism connecting the free endsof said levers including an expansible fluid pressure cylinder andpiston, and lever operating heads crossconnected to said cylinder andpiston whereby as said cylinder and piston expand said operating headscontract to draw said levers and abutments together and contract saidbrake band on said drum, said levers maintaining the axes of said brakeband and drum substantially coincident thereby contracting said brakeband uniformly defined by the claims hereto appended and I wishtherefore not to be restricted l pair of levers pivoted to said lframeopposite said band positioning members when said brake mechanism isinoperative, abutment means secured to opposite endsof said brake band,said ends and abutments being positioned between a pair of saidadjustable brake band positioning members, a

abutment members, adjustable means abuttingly connecting the free end ofeach of said levers with the adjacent abutment means, and a floatingoperating mechanism connecting the free ends of said levers including anexpansible fluid pressure cylinder and piston, and lever operating headscross-connected to said cylinder and piston whereby as said cylinder andpiston expand said operating heads contract to draw said levers andabutments together and contract said brake band on said drum, saidleversmaintaining the axes of said brake band and drum substantiallycoincident thereby contracting said brake band uniformly whereby all ofthe frictional area thereof is brought substantially simultaneously intocontact with the drum and thereafter to exert pressure upon saidabutments to contract said brake band to apply braking pressure.

4. A reversible balanced self-energizing brake mechanism including incombination spaced brake band positioning means, a'brake drum, a onepiece brake band adapted to float upon said drum extending over theperiphery thereof in excess of 270 degrees, said brake band beingnormally expanded away from said drum and against said brake bandpositioning means when said brake mechanism is inoperative, abutmentmeans on opposite ends of said brake band, a pair of levers each pivotedsubstantially centrally of the length of said brake band outside theconfines thereof, adjustable means abuttingly connecting the free end ofeach of said levers with the adjacent abutment means, and a oatingoperating mechanism connecting the free ends of said levers including anexpansible uid pressure cylinder and piston, and lever operating headscross-connected to said cylinder and piston whereby as said cylinder andpiston expand said operating heads contract to draw said levers andabutments together and contract said brake band on said drum, saidlevers maintaining the axes of said brake band and drum substantiallycoincident thereby contracting said brake band uniformly whereby all ofthe frictional area thereof is brought substantially simultaneously'into contact with the drum and thereafter to exert pressure upon saidabutments to contract said brake band to apply braking pressure.

5. A nui-d actuator structure including a body member forming a cylinderhaving an open and a closed end, part of said body member forming abifurcated head adjacent the open end of said cylinder which head isadapted to be connected to a member to be operated, said body memberhaving oppositely disposed spaced guide means extending along its sides,a piston in said cylinder, a yoke extending through the bifurcation insaid head abutting said piston, the sides thereof operating in saidoppositely disposed spaced guide means, a head adapted to be connectedto another member t0 be operated connecting the ends of said yokeadjacent the closed end of said cylinder, each of said heads havingoppositely disposed aligned bosses, and spring means interposed betweensaid aligned bosses urging said heads apart whereby upon movement ofsaid piston toward 9 the open end of said cylinder said two heacls willbe moved'toward each other.

ARTHUR L. LEE.

REFERENCES The following references are of record in the file of thispatent:

UNITED STATES PATENTS N unber Name Date Ericson Oct. 10, 1939 Pierce etal. Dec. 5, 1939 Loughead Dec. 4, 1917 Number

